CPW-Fed Antenna Design with Increased Bandwidth and WLAN Band-Filtering for UWB Systems

A compact coplanar waveguide (CPW)-fed monopole antenna with improved bandwidth and a band-notched function is proposed for ultra-wideband (UWB) applications. The antenna configuration is composed of a modified circular-ring radiation patch with a cross-strip and a pair of protruded arms and a semi-circular ground plane. It is designed on a low-profile FR-4 substrate with properties of ε= 4.4, δ= 0.02, and h=1.6 mm. By modifying the ground plane and also adding a cross-strip into the circular-ring radiation patch, the impedance bandwidth of the antenna for S11≤-10 can be improved significantly. The band-notched characteristic of the design is achieved by using the pair of protruded arms. The proposed antenna exhibits a wide usable fractional bandwidth from 3.1 to 24 GHz and a frequency notch-band in 5.5 GHz of WLAN systems. The performance of a 4×4 MIMO configuration for the proposed UWB antenna is also studied and good results are achieved.